Abstract: Employee #1 was repairing a concrete pump at the site of a new hotel. Nearby, an electrical contractor and a coworker were installing electric lighting from a wooden box on the forks of an extensible telescoping forklift boom. The forklift boom was extended forward of the cab to its maximum reach, as was the auxiliary, the boom base which slides from the rear to the front of the truck section. This resulted in a boom angle of approximately 30 degrees above horizontal. The boom was extended over the malfunctioning pump that Employee #1 was trying to repair when the forklift tipped forward and the box with the two electrical workers fell approximately 20 ft. The box struck Employee #1 on the head and knocked him to the ground. He sustained injuries, for which he was hospitalized. The forklift boom came to rest on top of the pump water tank and a hose reel, leaving the box suspended approximately 3 ft above Employee #1. The two workers inside the box were not injured.